Implement oh no 404 page

404.rst

@@ -0,0 +1,11 @@
+:orphan:
+
+The Requested Page Was Not Found
+================================
+
+The page you were searching for does not exist. Please view the sidebar for a list of available pages.
+
+.. image:: images/404-oh-no.png
+   :alt:
+
+"oh no" comic credit to `Dorris Comics <https://twitter.com/dorrismccomics>`__

conf.py

@@ -10,7 +10,7 @@
 # add these directories to sys.path here. If the directory is relative to the
 # documentation root, use os.path.abspath to make it absolute, like shown here.
 #
-# import os
+import os
 # import sys
 # sys.path.insert(0, os.path.abspath('.'))
 
@@ -28,9 +28,20 @@
 # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
 # ones.
 extensions = [
-    'sphinx_tabs.tabs', 'sphinx_sitemap'
+    'sphinx_tabs.tabs', 'sphinx_sitemap', 'notfound.extension'
 ]
 
+master_doc = "index"
+
+# Only one langauge supported, no URL prefix
+# This is only needed when deploying a non-RTD server
+on_rtd = os.environ.get('READTHEDOCS') == 'True'
+
+if on_rtd:
+   notfound_no_urls_prefix = False
+else:
+   notfound_no_urls_prefix = True
+
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ['_templates']
 

requirements.txt

@@ -0,0 +1,3 @@
+sphinx_sitemap
+sphinx-tabs
+sphinx-notfound-page